Molding Switch Handles

A color experiment waiting to come out of the new mold.

A picture of the top half of the old mold.

Bottom half of the old mold.

Both halves stuck together. In real use there should be rubber banding around the two pieces, to press them firmly together.

Pretending to inject plastic into a hole drilled in the top. (I'd squirt in plastic until it began to flow out the other holes and pool on top.)

Here is a mold being made. The bottom part with the white stuff is Sculpey modeling clay, which will be removed when this pour cures. Then I will apply mold release and pour the other side. (The spill is the Silicone RTV without the hardener added. Also visible are chopsticks used for stirring, and a bottle of colorant.)

Blobs of Sculpey. I chose it because I don't have to worry about it hardening up on it's own. (It stays soft until baked.)

A tub of silicone RTV, for making molds.

Silicone RTV hardener. This stuff is color coded. The green takes 24 hours to cure. The long lead time means you can take your time, and that the bubbles have time to pop.

Quick Cast B. This is the part of the plastic you add the colorant to. You can see the colorant transfer from my gloves.

Quick Cast A. This hardens the B. You can see even more colorant has got on this bottle.

Time to open tonight's color experiment. I can see there is way too much ooze between the handles, so I know next time I need to press the sides top and bottom of the mold more firmly together. (That also caused a lot of air to run back in through the holes in the top.)

The handles peeled out of the bottom half the mold. Lots of plastic to trim.

The trimmed pieces. It also became clear during trimming that there are alignment issues, so I will have to add more pins to ensure the top and bottom halves of the mold remain aligned.

Another shot of the same thing, but without the flash.

The box the Sculpey came in.

Another shot, with the original handles for comparison. The color is much better, and is probably acceptable for "yellow" handles. Now to figure out "brown" (Chinese red?).

Last updated on 12/20/11 09:11